diff --git a/aula202-calculadora/main.py b/aula202-calculadora/main.py
index be1f6a8..34e95d2 100644
--- a/aula202-calculadora/main.py
+++ b/aula202-calculadora/main.py
@@ -5,11 +5,13 @@ from info import Info
 from main_window import MainWindow
 from PySide6.QtGui import QIcon
 from PySide6.QtWidgets import QApplication
+from styles import setupTheme
 from variables import WINDOW_ICON_PATH
 
 if __name__ == '__main__':
     # Cria a aplicação
     app = QApplication(sys.argv)
+    setupTheme()
     window = MainWindow()
 
     # Define o ícone
diff --git a/aula202-calculadora/styles.py b/aula202-calculadora/styles.py
new file mode 100644
index 0000000..c25f2c5
--- /dev/null
+++ b/aula202-calculadora/styles.py
@@ -0,0 +1,38 @@
+# QSS - Estilos do QT for Python
+# https://doc.qt.io/qtforpython/tutorials/basictutorial/widgetstyling.html
+# Dark Theme
+# https://pyqtdarktheme.readthedocs.io/en/latest/how_to_use.html
+import qdarktheme
+from variables import (DARKER_PRIMARY_COLOR, DARKEST_PRIMARY_COLOR,
+                       PRIMARY_COLOR)
+
+qss = f"""
+    PushButton[cssClass="specialButton"] {{
+        color: #fff;
+        background: {PRIMARY_COLOR};
+    }}
+    PushButton[cssClass="specialButton"]:hover {{
+        color: #fff;
+        background: {DARKER_PRIMARY_COLOR};
+    }}
+    PushButton[cssClass="specialButton"]:pressed {{
+        color: #fff;
+        background: {DARKEST_PRIMARY_COLOR};
+    }}
+"""
+
+
+def setupTheme():
+    qdarktheme.setup_theme(
+        theme='dark',
+        corner_shape='rounded',
+        custom_colors={
+            "[dark]": {
+                "primary": f"{PRIMARY_COLOR}",
+            },
+            "[light]": {
+                "primary": f"{PRIMARY_COLOR}",
+            },
+        },
+        additional_qss=qss
+    )
diff --git a/aula202-calculadora/variables.py b/aula202-calculadora/variables.py
index 30e74f3..d9c5d62 100644
--- a/aula202-calculadora/variables.py
+++ b/aula202-calculadora/variables.py
@@ -4,6 +4,11 @@ ROOT_DIR = Path(__file__).parent
 FILES_DIR = ROOT_DIR / 'files'
 WINDOW_ICON_PATH = FILES_DIR / 'icon.png'
 
+# Colors
+PRIMARY_COLOR = '#1e81b0'
+DARKER_PRIMARY_COLOR = '#16658a'
+DARKEST_PRIMARY_COLOR = '#115270'
+
 # Sizing
 BIG_FONT_SIZE = 40
 MEDIUM_FONT_SIZE = 24